Pressurized greenhouse

Abstract

A pressurized greenhouse and air conditioning system designed to optimize plant growth environments. The pressurized greenhouse includes a frame with a transparent covering membrane, vertical fans for maintaining uniform climate conditions, and a pressure control system to manage air intake and exhaust. To achieve precise temperature control, the air conditioning system employs evaporative cooling, air-water heat exchange, and a thermal battery heat exchanger. It circulates air using horizontal fans and utilizes stored thermal energy for heating and cooling modes. Heat rejection means, such as cooling towers or chillers, further enhance efficiency. This inventive system offers comprehensive climate control capabilities for optimal plant growth, making it an essential tool for greenhouse cultivation.

What is claimed is: 
     
         1 . A pressurized greenhouse comprising:
 a. a frame with a non-porous covering membrane thereover defining an enclosed greenhouse space, said covering membrane having a roof portion and at least one side wall and being at least partially transparent to allow sunlight to pass through;   b. a floor covering positioned within the greenhouse space and sealed to the bottom edge of the covering membrane;   c. a plurality of vertical fans attached within the greenhouse space in proximity to the roof portion of the covering membrane, said vertical fans, when actuated, capable of providing uniform climate conditions within the greenhouse space;   d. a pressure control means comprising:
 i. a primary pressure vent comprising a hinged outward-opening vent which opens to vent atmospheric air from inside the greenhouse space to the external environment when static pressure therein exceeds a primary pressure setpoint which is above a target operation pressure for the greenhouse; 
 ii. a secondary pressure vent comprising a hinged outward-opening vent which opens to vent atmospheric air from inside the greenhouse space to the external environment when static pressure therein exceeds a secondary pressure setpoint which is above the primary pressure setpoint; 
 iii. an active air intake device connecting the external environment and the greenhouse space to pump air from the outdoor environment into the greenhouse space if the operating pressure inside the greenhouse space falls below a selected intake pressure setpoint; and 
 iv. an under-pressure vent mechanism that will open to permit passive air intake into the greenhouse space from the external environment if the operating pressure inside the greenhouse space falls below the intake pressure setpoint and the active air intake device fails. 
   
     
     
         2 . The greenhouse of  claim 1  further comprising a dual door transition entrance connecting the greenhouse space and the outdoor environment, by operation of which the operating pressure inside of the greenhouse space is maintained on ingress or egress of people or material. 
     
     
         3 . An air conditioning system for a greenhouse space comprising:
 a. an evaporative cooling system for evaporating water into low humidity air within the greenhouse space;   b. an air-water heat exchanger mounted within the greenhouse space and comprising a water inlet and a water outlet for water circulation therethrough and having a drip pan thereunder for capturing condensate therefrom;   c. a plurality of horizontal fans mounted in proximity to said air-water heat exchanger capable of creating a horizontal airflow thereacross and through the greenhouse space;   d. a thermal battery heat exchanger comprising a water-containing shell section having a water inlet and a water outlet, and a plurality of air flow tubes comprising a heat transfer surface and including condensate drain therein;   e. a conduit connecting the water outlet of the air-water heat exchanger to the water inlet of the thermal battery heat exchanger;   f. a water recirculation pump having a recirculation intake and a recirculation discharge, the recirculation intake being connected to the water outlet of the thermal battery heat exchanger;   g. a recirculation discharge conduit connecting the recirculation discharge of the water recirculation pump to the water inlet of the air-water heat exchanger;   h. an indoor-air-flow mechanism that collects air from the greenhouse space in proximity to the air-water heat exchanger for injection into the air flow tubes of the thermal battery heat exchanger;   
       wherein the system is operated using a method comprising:
 a. establishing a target operating temperature having cooling and heating temperature setpoints above and below the target operating temperature for corresponding cooling or heating modes of operation until the target operating temperature is reached, and storing water in the shell section of the thermal battery heat exchanger in advance of operation; 
 b. actuating the horizontal fans to circulate air across the greenhouse space; 
 c. when the temperature within the greenhouse space reaches one of the heating or cooling temperature setpoints, activating a heating or cooling mode of operation by:
 i. actuating the water recirculating pump to send stored water from the thermal battery heat exchanger to the air-water heat exchanger by the water recirculating pump entering operation; 
 ii. when the cooling temperature setpoint is detected within the greenhouse space, entering a cooling mode of operation until the target operating temperature is reached by:
 1. activating the evaporative cooling system until the target operating temperature is reached in the greenhouse space; 
 2. actuating the mechanical indoor-air-flow mechanism to inject air for further cooling into the thermal battery heat exchanger; 
 3. releasing further cooled air from the air tubes back into the greenhouse space where the low humidity allows for continuous evaporative cooling; and 
 4. recirculating water exiting the air-water heat exchanger after thermal energy collection therefrom back into the thermal battery heat exchanger for thermal energy storage; 
 
 iii. when the heating temperature setpoint is detected within the greenhouse space, entering a heating mode of operation until the target operating temperature is reached by:
 1. actuating the indoor-air-flow mechanism to inject air to be heated into the thermal battery heat exchanger before release back into the greenhouse space; and 
 2. recirculating water from the air-water heat exchanger back into the thermal battery heat exchanger for thermal energy storage. 
 
 
 
     
     
         4 . The system of  claim 3  further comprising heat rejection means fluidly connected between the air water heat exchanger and the thermal battery heat exchanger. 
     
     
         5 . The system of  claim 4  wherein the heat rejection means comprises any one or more of a cooling tower, a chiller, a geothermal heat rejection system or an air cooler. 
     
     
         6 . The system of  claim 4  wherein water flow from the air-water heat exchanger is circulated through the heat rejection means before entering the thermal battery heat exchanger. 
     
     
         7 . The system of  claim 3  further comprising supplemental heating means for use when thermal energy collected in the air-water heat exchanger or stored in the thermal battery heat exchanger is insufficient to operate the system in heating mode. 
     
     
         8 . The system of  claim 7  wherein the supplemental heating means comprises any one or more of a waste heat recovery unit, a geothermal heating system, a backup heater or a boiler. 
     
     
         9 . The system of  claim 5 , wherein the air conditioning system is capable of performing thermal energy collection and storage, condensation, excess heat rejection, and supplemental heat collection.